EP2221196B1 - Twist beam axle and method for its production - Google Patents

Description

The invention relates to a torsion beam axle with the features in the preamble of patent claim 1 and a method for their preparation according to the features in the preamble of claim 3.

In the basic structure, torsion beam axles consist of two lateral longitudinal arms, to which the wheels are connected via welded attachments. A preferred constellation for achieving a high rigidity with low weight is the design of the side arms in tubular form in direct connection of a Radträgerflansches. This results in the problem that a thin-walled tube, which is used for the side arm, must be welded to a relatively thick-walled flange plate of Radträgerflansches. The thicker material of the Radträgerflansches deprives the welding process heat, with the result that different Einbrandtiefen be achieved when varying the welding gap width. It has been shown that such process fluctuations have a large impact on the component life. The incompletely welded welds may tear from the inside out, initiating the crack through the non-welded portions of the weld gap.

With specially manufactured prototypes it could be proven that with complete welding of the welding gap the lifetime requirements were fulfilled. The assurance of a complete penetration welding is not sufficiently process reliable implemented, since the required for this larger welding gap and the higher welding energy has a burn through and thus a collapse of the weld result.

The state of the art is the WO 2008/108166 A1 to name a torsion beam axle with held by tubular side arms Radträgerflanschen, which are welded to the tubular side arms. At the Radträgerflanschen directed to the side arms exhibition is formed, which is adapted to an inner contour of the tubular side arm.

The JP 2000 238502 A also discloses a torsion beam axle having wheel support flanges held by tubular side arms which are welded to the tubular side arms. At the Radträgerflanschen directed to the side arms exhibition is formed, which is adapted to an inner contour of the tubular side arm.

The state of the art is still on the DE 10 2006 015672 A1 relating to an embodiment of a vehicle axle, in which fastening domes are integrally formed on an axle body. Attached thereto and welded are half shells of the trailing arm or the support arm. Due to the shape of the protruding from the cross-sectional contour of the axle body mounting dome arise at their flanks favorable Schweißbadstützen for pulling the welds.

On this basis, the invention is based on the object to show a composite beam axis with a held by tubular side elements Radträgerflansch, in which a process-reliable connection of the Radträgerflansche is possible with the side arms. Furthermore, an alternative method for producing such a torsion beam axle is to be shown. The objective part of this problem is solved by claim 1.

A corresponding method is the subject of patent claim 3.

The respective dependent claims relate to advantageous developments of the inventive concept.

In the case of the torsion beam axle according to the invention, it is provided that an orientation directed towards the side arm is formed on the wheel carrier flanges, which is adapted as a welding bath support to an inner contour of the tubular side arm. In the fine blanking process, the Radträgerflanschplatte is embossed so that the exhibition produced by Verprägen the inner tube contour of the side arm maps. As a result, the exhibition acts as a welding pool support, covering the welding gap to one side. The welding takes place from the outside. Therefore, the exhibition is adapted in the form of a Schweißbadstütze to the inner contour of the tubular side wall. Decisive here is the inner contour in the contact area to the side arm. In this way it is possible to weld through the weld process reliable to the welding gap, with a burn through and thus a collapse of the weld is prevented by the Schweißbadstütze.

Such torsion beam axles can be produced reliably with regard to the connection between the side arms and the Radträgerflanschen. By embossing is also possible to introduce in the Radträgerflansche more spacers that can be made adjacent to the trained as Schweißbadstütze exhibition in a single operation. Due to the constant, somewhat larger welding gaps, the required high welding power can be introduced without the melted weld metal being able to drip out of the weld seam. This is prevented by the trained as Schweißbadstütze exhibition. In the context of the invention, the penetration depth can thus be set so high by higher welding currents and correspondingly wider welding gaps that a complete penetration welding of the weld is possible, with the result that the component life compared to components that are formed without such Schweißbadstützen, much less fluctuates. The production process according to the invention is process-reliable.

Since embossing of the wheel carrier flanges takes place anyway during production of the exhibition, a bevel can optionally be formed by embossing as seam preparation on the wheel carrier flange. With a single embossing step, the exhibition serving as a welding bath support, the spacers for adjusting the welding gap width, and the seam preparation can thus be formed.

It is also possible within the scope of the invention to design the Radträgerflansche as a forged part or even as a casting, wherein the Schweißbadstütze is prepared by forging or deformation. The wheel hub may be integrally formed with these components in the Radträgerflansch.

Figur 1

eine perspektivische Ansicht eines Teilbereichs einer Verbundlenkerachse an einem rohrförmigen Seitenarm befestigten Radträgerflansch (Stand der Technik);

Figur 2

eine schematische Darstellung des Radträgerflansches der Figur 1 mit einem Endabschnitt des rohrförmigen Seitenarms im Querschnitt (Stand der Technik);

Figur 3

eine perspektivische Ansicht einer Verbundlenkerachse mit einem erfindungsgemäßen Radträgerflansch;

Figur 4

den Radträgerflansch der Figur 3 und den rohrförmigen Seitenarm im Querschnitt;

Figur 5

den erfindungsgemäßen Radträgerflansch der Figuren 3 und 4 in Blickrichtung auf die Befestigungsseite des Seitenarms und

Figur 6

eine alternative Ausführungsform, bei welcher der Radträgerflansch einteiliger Bestandteil eines Achsträgers mit daran ausgebildeter Radnabe ist.

The invention will be explained in more detail with reference to an embodiment shown in the drawings. It shows:

FIG. 1

a perspective view of a portion of a torsion beam axle on a tubular side arm mounted Radträgerflansch (prior art);

FIG. 2

a schematic representation of Radträgerflansches the FIG. 1 with an end portion of the tubular side arm in cross section (prior art);

FIG. 3

a perspective view of a torsion beam axle with a Radträgerflansch invention;

FIG. 4

the Radträgerflansch the FIG. 3 and the tubular side arm in cross section;

FIG. 5

the Radträgerflansch invention FIGS. 3 and 4 in the direction of the attachment side of the side arm and

FIG. 6

an alternative embodiment in which the Radträgerflansch is an integral part of an axle carrier with hub formed thereon.

FIG. 1 shows a perspective view of a wheel-side end of a twist beam axis. It can be seen a tubular side arm 1, at the end of a planar Radträgerflansch 2 is secured by welding technology.

FIG. 2 shows the arrangement of FIG. 1 on average. It can be seen that the wall thickness of the tubular side arm 1 is substantially smaller than the wall thickness of Radträgerflansches 2. In addition, meets the tubular side arm 1 at a relatively acute angle to the Radträgerflansch 2, whereby a complete penetration welding the seam difficult and process reliability is impaired ,

FIG. 3 shows a Radträgerflansch 2 in the embodiment of the invention. It can be seen that the Radträgerflansch 2 seen from this perspective has a depression. This depression leads on the opposite side of Radträgerflansches 2 to an exhibition 3, as in FIG. 4 can be seen. From the sectional view of FIG. 4 It is clear that the exhibition 3 is adapted in the form of a Schweißbadstütze to the inner contour of the tubular side arm 1. The exhibition 3 thus serves as Schweißbadstütze when the tubular side arm 1 is welded from the outside to the Radträgerflansch 2. Furthermore, it is off FIG. 4 to recognize that the upper end of the tubular side arm 1 in the image plane contacted the Radträgerflansch 2, while the lower end at a distance from the Radträgerflansch 2 extends. This is due to the fact that in the selected cutting plane at the upper end a spacer 4 is arranged, as in FIG. 5 is shown. FIG. 5 shows the back of the in FIG. 3 illustrated Radträgerflansches. There are three spacers 4 distributed over the circumference of Radträgerflansches 2 arranged. The spacers 4 are small hump-like deformations, which are directly adjacent to the exhibition 3 and are also made by embossing. The spacers 4 are used to set the welding gap width, so that you can work with correspondingly larger, constant over the circumference welding gaps and higher welding currents.

Out FIG. 4 Finally, a chamfer 5 in the immediate vicinity of the spacer 4 or the exhibition 3 shows. The circumferential chamfer 5 can be generated simultaneously during the Verprägevorgangs for the preparation of the spacer 4 and the exhibitions 3.

As a result, in the region of the lower weld area, which is difficult to machine, the FIG. 4 a seam preparation can be provided inexpensively, which additionally favors the process reliability.

The embodiment of the FIG. 6 is different from those of FIGS. 3 to 5 in that a forging-technically produced wheel carrier 6 is provided with integrated wheel hub 7.

Reference numerals:

1 -

sidearm

2 -

wheel carrier flange

3 -

exhibition

4 -

spacer

5 -

chamfer

6 -

wheel carrier

7 -

wheel hub

Claims (4)

1. Twist-beam rear axlecomprising wheel carrier flanges (2) which are held by tubular side arms (1) and are welded to thetubular side arms (1), a raised portion (3) that faces the side arms (1) being formed on the wheel carrier flanges (2) and being adapted toan inner contour of the tubular side arm (1) in the form of a weld pool support, characterised in that the wheel carrier flanges (2) comprise a plurality of spacers (4) that are adjacent to the raised portion (3) that is designed as a weld pool support.
2. Twist-beam rear axle according to claim 1, characterised in that a chamfer (5) is formed on the wheel carrier flanges (6) as a joint preparation.
3. Method for producing a twist-beam rear axle, in which a wheel carrier flange (2) is welded to a tubular side arm (1) of the twist-beam rear axle, a raised portion (3) that serves as a weld pool support beingadapted to an inner contourof the side arm (1) in terms of the shape thereof and engaging with the side arm (1) when in the weld position, said side arm being welded on the outside to the wheel carrier flanges (2) in such a way that the penetration depth extendsas far as into the raised portion (3), characterised in that a plurality of spacers (4) for determininga weld gap width are formed such that they are adjacent to the raised portion (3) that forms the weld pool support, and the wheel carrier flange (2) being stampedin the direction of the side arm (1) for the purpose of forming the raised portion (3).
4. Method according to claim 3, characterised in that a chamfer (5) is formedon the wheel carrier flanges (2) as a joint preparation.

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